American Board of Internal Medicine (ABIM) Certification Practice Exam

If a patient has a SAAG of 1.1 g/dL and total protein greater than or equal to 2.5 g/dL, what condition may they have?

1. Nephrotic syndrome

2. Cirrhosis

3. Cardiac ascites

4. Infectious ascites

The correct answer is: Cardiac ascites

A serum-ascites albumin gradient (SAAG) of 1.1 g/dL indicates that the ascitic fluid is transudative in nature. This finding is crucial in determining the underlying cause of ascites. The level of total protein in the ascitic fluid, at greater than or equal to 2.5 g/dL, suggests that the ascitic fluid is rich in protein. When associating these two findings—transudative fluid (as indicated by the SAAG) and high levels of protein—the most likely condition is cardiac ascites. Cardiac ascites typically occurs due to heart failure, where increased venous pressure leads to transudative ascites. The high total protein level can be attributed to the protein that leaks out of the circulation due to increased pressure, reflecting the compromised ability of the heart to pump effectively. In contrast, nephrotic syndrome would generally present with a different SAAG and usually with higher levels of protein in the urine, which manifests as low SAAG due to nephrotic fluid characteristics. Cirrhosis typically presents with a higher SAAG and a lower protein level in ascitic fluid. Infectious ascites commonly shows an elevated white blood cell count and may not